hermann



Oct. l 25, 1966 o. HERMANN 3,280,651

DIGITAL ACTUATOR Filed April 16, 1964 4 Sheets-Sheet 1 O UEE H {L/ )1% U H I?? o KD a? N l O t :L o: A I 3 S H 8 Q s I wwwwvv o kan s, o M :I y" 9X o o 7214A@ g TQ-LL..

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Oct. 25, 1966 o. HERMANN 3,280,651

DIGITAL AGTUATOR Filed April 16, 1964 4'Sheets-Sheet 4 los FIG-5 INVENTOR. O TTO H E R HA NN Tm a TW ATTORNEYS United States Patent Oli-ice 3,289,551 Patented Oct. 25, 1966 3,280,651 DIGTAL ACTUA'IOR Otto Hermann, Cincinnati, Ghia, assigner to The R. K.

Le Blond Machine Tool Co., Cincinnati, Ohio, a corporation of Delaware Filed Apr. i6, 1964, Ser. No. 360,192 15 Claims. (Cl. 74--365) This invention relates to an actuator and is particularly concerned with an actuator arrangement operable for producing precise predetermined movements of an element moved thereby through small increments.

There are many instances when it is desired for an element to 'be moved any selected multiple of a predetermined increment. This might occur, for example, in connection with a multiple position hydraulic valve or the like. The present invention proposes the provision of a simple reliable inexpensive actuator arrangement of the type that will produce movement of a movable member through any selected multiple of a predetermined increment. In a sense, the present invention is thus concerned with what could be referred to as a digital actuator because the actuation of the member to be moved is some whole multiple of a given unit.

With the foregoing in mind, an object of the present invention is the provision of an actuator arrangement of the nature referred to which is extremely reliable -in operation.

Another object of this invention is the provision of an actuator of the nature which is inexpensive to construct.

Still another object of this invention is the provision of an actuator of the nature referred to which is widely applicable to any given situation where a member is to be moved by a multiple of some given unit.

These and other objects and advantages of this invention will become more apparent upon reference to the following specification taken in connection with the accompanying drawings, in which:

FIGURE 1 is a somewhat yschematic view showing an actuator according to the present invention arranged for controlling a valve associated with a hydraulic gear shifting mechanism;

FIGURE 2 is a view looking in at the side of the actuator according to this invention drawn at somewhat enlarged scale;

FIGURE 43 is a view looking in from the right side of FIGURE 2 and drawn at the same scale;

FIGURE 4 is a vertical sectional View indicated by line 4 4 on FIGURE 2;

FIGURE 5 is a view showing a single cam of the actuator and indicating the manner of construction thereof to insure ac-curate operation of the device, and

FIGURE 6 is a schematic view of a typical wiring diagram for `controlling the actuator.

Referring to the drawings somewhat more in detail, FIGURE 1 shows in fragmentary form a gear box arrangement, for a lathe, for example, in which there is an input motor 10 driving through an electrically operated clutch 12 into a shaft 14 and which shaft drives a lubricating oil pump 16. Shaft 14 has gears 18 thereon adapted for engagement by change gear means 20 on another shaft 22. Change gear means 20 are movable into their several operative positions by a shifter fork 24 mounted on ram 26 of a hydraulic motor. The transmission includes other shafts and change gears, not shown, with the change gears being movable by shifter forks and other actuating elements on rams 28 of other hydraulic motors.

The control of fluid to the motors to actuate their respective rams is under the control of a plate-like valve member 30 which is supplied with pressure iluid from a pump 32 driven by a motor 34.

Shifting of valve 30 into its several positions is accomplished by teeth 36 on one edge of the valve member meshing With a pinion 38 on a shaft 40 that extends into a rotary hydraulic servo-motor 42. The servo-motor include-s an input shaft 44, and it Will be understood that the shaft 40 follows shaft 44 as the latter is rotated in one direction or the other with pressure fluid supplied to the servo-motor via conduit 46 supplying the power necessary for driving shaft 40 so that shaft 44 is substantially completely unloaded.

Shaft 44 has connected thereto a manually operable knob 48 which can be availed of Ifor rotating shaft 44 to any desired position.

Shaft 44 is also connected with another shaft 50 by the chain and sprocket means 52 so that shaft 44 can be rotated by rotating shaft 50. Shaft 50 carries a pinion 54 meshing with a rack 56 which extends completely through the actuator 58 of the present invention where, at its extreme end, rack 56 meshes with an actuating pinion 60 forming a part of the actuator.

At this point it will be evident that rotation of actuator pinion 60 will cause movement of rack 56 and this will bring about rotation of shaft 50.

Turning now to FIGURES 2, 3 and 4, it will be seen that actuator pinion 60 is mounted on a shaft 62 carried in a bearing block 64 attached to the frame 66 of actuator 58. Also mounted on shaft 62 is a smaller pinion 68 that meshes with teeth 70 on one of a pair of guide bars 72 that are slidably guided for vertical movement on opposite sides of frame 66 of the actuator by means of the guideways 74 formed in the said side walls.

The guide bars 72 are interconnected by cross bar means 76 extending through the frame of the actuator and of which there may be two or more so that the guide bars and cross bars form a rigid framework slidable on the main frame of the actuator.

Vertical movement of the guide bars is accomplished by a cam block 78 carried by the upper cross bar 76 and resting on top of the uppermost one of a plurality of cams 39, 82, 84, 86, 88 and 90. The lowerrnost of the cams 90 rests on a stationary cam block 92 in the frame.

Blocks 78 and 92 and all the cams are hardened to minimize wear thereof.

Each cam has an actuating pin 94 extending therethrough and traversing a central bore 96 in the respective cam. Each pin 94 is engaged by a slotted rotator rod 98 which leads to the pertaining one of a plurality of rotary solenoids 106 carried by the frame of the actuator. Each rotary solenoid litt) will impart substantially 90 of rotation to its connected cam upon energization of the solenoid and will permit the cam to return to its original position when the solenoid is de-energized. The actuator rods 98 are not only exibly connected with their respective cams, but are also flexibly connected to their pertaining solenoids by means of the pins 102.

Each of the cams is formed as indicated in FIGURE 5 with a circular hub portion 104 by means of which the cams are mounted in position in the actuator between spaced plates. Each cam also has a shaped peripheral portion 166 which, as will be seen in FIGURE 5, consists of two dametrically opposite ats 16S located on the smallest diameter of the cam and two portions, also diametrically opposite each other, at which are concentric with the center of the cam. Each of these portions may extend over about 30 of the circumference of the cam. The fiat portions 108 are joined with the circular portions 110 by the rises 112.

The cams are so formed so that the difference between the diameter of the cam in the centers of the flats and the diameter of the cam at the circular portions represents the amount of movement that can be imparted by that particular cam when it is rotated by its solenoid operator.

In the arrangement shown in the drawings, for example, cam 90 has a diametral difference of 1/2 of an inch; cam 8S a difference of 1/16 of an inch; cam 86 a difference of 1A; of an inch; cams 82 and 84 a difference of 1A inch eachgcam 80 a difference of 1/2 inch. The cams are thus able to provide for actuation of cam block 78 a distance which is any multiple of 1/32 of an inch from one up to thirty-nine. For example, for 1/32 of an inch movement, only cam 90 would be turned by its actuator; for 2/32 or lA inch movement, only cam 88 would be rotated by its actuator; for 3/32 inch movement, both cams 88 and 90 would be rotated by their respective actuators, and so on upto 3%2 of an inch which would be the amount of movement imparted to block 78 if all of the cams were rotated by their respective actuators. Any unit dimension other 'than 1/32 inch could, of course, be employed.

It will be levident that because of the flats 108 and circular portions 110 on the cams, precise indexing between their rotated and rest positions and yvice versa is not critical so that accurate results will obtain without the necessity of providing fory an exact angular movement of the cams at all times.

When the cams in FIGURE 3 are rotated, rack 56 kwill move leftwardly and the rack is supported in its adjusted position by a pawl 120 which is in the form of a leaf spring and which is mounted on a plunger 122 reciprocably supported in the frame while being held against rotation therein by a stationary tooth 124 engaging a groove in the shaft.

The shaft is adapted for movement leftwardly of its FIGURE 3 position to cause the end of pawl 120 to cam down the inclined ends of pins 126 and release rack 56 by still another rotary solenoid 128 that carries a slotted block 130 on the end of its shaft. This slotted block receives pin 132 on plunger 122, so that when solenoid 128 is energized plunger 122 will be thrust leftwardly and pawl 120 will be cammed downwardly and rack 56 will be released. The actuated mechanism may return to its lowered position by its own Weight or there may be provided a return spring 134 if so desired. In any case, a precise amount of travel can be given the rack 56 and it can be retained in this position and then returned to a rest position at will.

The actuator according to the present invention can be embodied in an electric control circuit as :shown in FIGURE 6. In FIGURE 6 power lines L1 and L2 supply current through a normally open start switch 150 to the coil of a relay R1 which has a holding blade 152 in series with which is a normally closed stop switch 154.

Relay R1 has a normally open blade 156 in circuit with the aforementioned transmission drive motor 10.

A second start switch 158 is in circuit with the actuating coil of a relay R2 which relay has a holding blade 160 in series with a second normally closed stop switch 162.

Another normally open blade 164 of relay R2 is in circuit with the actuatingv coil of clutch 12 which forms the driving connection between motor and the transmission.

A normally closed blade 166 of relay R2 is connected with line 168 which leads through selector switches 10051, 100b, 100e, 100d, 100e and 100,1t to the several rotary solenoids 100 previously referred to andfeach of which, it is understood, pertains to a different one of the aforementioned cams of the actuator.

The rotary solenoid 128 for rotating rack 56 is connected by a line 170 through a blade 172 of start switchl 158 which closes when the said start switch is depressed.

The aforementioned line 168 is also provided with a pressure switch operated blade 174 which remains open as long as pump 16 is developing pressure, but which will close when the pressure from .pump 16 reduces substantime, any preselection of the switches a through 100f can be made. This preselection, however, will be without effect until switch 162 is opened to de-energize relay R2. When this relay is de-energized, clutch 12 will be opened and the transmission will come to a halt and the pressure from pump 16 will decay to zero, and at that time, switch 174 will close whereupon, due to the now closed blade 166 f of relay R2, the solenoids 100 having their switches closed will be energized causing the cames to rotate and effecting shifting of valve member 30. The pressure from pump 32 driven by motor 34 will then accomplish shiftingy of rams 26 and 28. Thereafter, when switch 158 is again closed, relay R2 will close again picking up clutch 12 to restart the transmission while simultaneously `de-energizing all of the energized ones of solenoid 100. Simultaneously blade 172 will close and energize reset solenoid 128 so that the entire system will return to its original condition. While the transmission is operating, switches 100e to 100)C can be readjusted to any desired position for a new speed setting of the transmission.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions; and accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

I claim:

1. An actuator comprising; a frame, a stationary first bearing block and a movable second bearing block in said frame, a plurality of rotary cams in the frame arranged in alignment and bearing ybetween said iblocks, and means selectively operable for rotating said carns from one po sition to another to cause controlled movement of said second bearing block in said frame.

2. An actuatorv comprising; a frame,v a stationary first bearing block and a movable second bearing block in said frame, a plurality of substantially elliptical rotary cams in the frame arranged in alignment and bearing between said blocks, and means selectively operablev for rotating said cams from a first position wherein ,the major axes thereof are substantially perpendicular to aline joining the centers of the cams to a second position wherein the minor axes thereof are substantially perpendicular to said line.

3. An actuator comprising; a frame, a stationary first bearing block and a movable second bearing -block in said frame, a plurality of substantially elliptical rotary cams in the frame arranged in alignment and bearing between said blocks, and means selectively operable for rotating saidcams from a first position wherein the major axes thereof are substantially perpendicular to a line joining the centers of the calms to a second -position wherein the minor axes thereof are substantially perpendicular to said line, earch said cam having regions at the ends of said major axis concentric with the center of the cam.

4. An actuator comprising; a frame, a stationary first bearing block and a movable second bearing block in said frame, a plurality of substantially elliptical rotary cams in the frame arrangedin alignment and bearing between said blocks, and means selectively operable for rotating said cams from a rst position wherein the major axes thereof are substantially perpendicular to a line joining the centers of the cams to a second position wherein the minor axes thereof are substantially perpendicular to said line, each said cam having regions at the ends of said major axis concentric with the center of the cam, and regions at the ends of said minor axis which are flat and perpendicular to the minor axis.

5; An actuator comprising; a frame, said frame defining a channel, a plurality of cams in serial relation in the channel having freedom in the channel to move in the direction of the length of the channel, each cam having a larger diameter and a smaller diameter, a stationary rst bearing block in the frame at one end of the channel on which fthe cam :at one end of the series of cams rests, a movable second bearing block movably guided in the frame spaced along the channel from said first bearing block and engaged by the cam at the other end of said series of cams, a rotary actuator for each cam mounted on the frame, a exible drive connection from each actuator to its respective cam, each actuator being operable when energized to rotate its respective cam to position the larger diameter thereof in the direction of the length of said channel and when de-energized to rotate the respective cam to position the smaller diameter thereof in the direction of the length of the channel, and means for selectively energizing said actuators.

6. The arrangement according to claim 5 wherein said cams are substantially elliptical whereby the said larger and smaller diameters thereof are at substantially right angles to each other and said rotary actuators rotating said cams substantially 90.

7. The arrangement according to claim 5 which includes detent means operable to retain said second bearing block in the respective shifted position into which it is moved by rotation of said cams, and means for disengaging sai-d detent means to release said second bearing block from its respective shited position.

S. The arrangement according to claim 5 wherein a rack is provided connected to said second bearing block, a pinion rotatable on the frame meshing with the rack, a toothed bar reciprocably guided in the frame, and a gear connected to said pinion and meshing with said toothed bar.

9. In combination with a transmission having shiftable gears, hydraulic motor means connected to said gears to effect the shifting thereof, valve means in circuit with said hydraulic motor means to control the movement thereof, and actuator means for shifting said valve means comprising a frame, a stationary rst bearing :block and a movable second bearing block in said frame, :a plurality of rotary cams in the frame arranged in alignment and bearing between said blocks, and means selectively operable for rotating said cams from one position to another to cause controlled movement of said second bearing block in said frame, said second block Abeing operatively connected with said valve means to shift the valve means into any of a plurality of predetermined operative positions.

10. The arrangement according to claim 9 which ncludes a drive motor for the transmission, a source of uid for said hydraulic motor means in circuit with said hydraulic motor means and said valve means, and control circuit means for controlling the energization of said drive motor and said source and operable to prevent energization of said source during energizaition of said drive motor.

11. In combination with a transmission having shiftable gears, hydraulic motor means connected to said gears to effect the shifting thereof, valve means in circuit with said hydraulic motor means to control the movement thereof, a shaft operatively connected to said valve member rotatable for shifting the valve member, a rotary servo-motor lhaving -its output side connected to said shaft, and actuator means for adjust-ing the input side of said servo-motor comprising, a frame, said frame dening a channel, a plurality of cams in serial relation in the channel having freedom to rotate in the channel and to move in the direction of the length of the channel, each cam having a larger diameter and a smaller diameter, a stationary rst bearing block in the frame at one end of the channel on which the cam at one end of the series of cams rests, a movable second bearing block movably guided in the frame spaced along the channel from said rst bearing block and engaged by the cam at the other end of said series of cams, a rotary actuator for each cam mounted on the frame, a flexible drive connection from each actuator to its respective cam, each actuator being operable when energized to rotate its respective cam to position the larger diameter thereof in the direction of the llength of said channel and when de-energized to rotate the respective cam to position the smaller diameter thereof in the direction of the length of the channel, and means for selectively energizing said actuators, said second bearing block being operatively connected with the input side of said servo-motor.

12. An arrangement according to claim 11 wherein said rotary actuators are electrically operable, means for preselecting the actuators to lbe energized for shifting said valve means.

13. An arrangement according to claim 12 which includes manual means for adjusting said valve means independently of said actuators.

14. An actuator comprising; a frame, a stationary first bearing block and a movable second bearing `block in said frame, a plurality of substantially elliptical rotary cams in the frame arranged in alignment and bearing between said blocks, and means selectively operable for rotating said cams from a rst position wherein'the major axes thereof are substantially perpendicular to a line joining the centers of the cams to a second position wherein the minor axes thereof are substantially perpendicular to said line, said cams varying in eccentricity -by whole multiples of a predetermined basic unit measurement.

15. An actuator comprising; a frame, a stationary first bearing block and a movable second bearing block in said frame, a plurality of substantially elliptical rotary cams in the frame arranged in alignment and bearing between said blocks, and means selectively operable for rotating said cams from -a rst position wherein the major axes thereof are substantially perpendicular to a line joining the centers of the cams to a second position wherein the minor axes thereof are substantially perpendicular to said line, each said cam having regions at the ends of said major axis concentric with the center of the cam, and regions at the ends of said minor axis which are at and perpendicular to the minor axis, said cams including at least a first cam with an eccentricity of one unit, one cam with an eccentricity of two units, one cam with an eccentricity of four units, two cams with an eecentricity of eight units, and one `cam with an eccentricity of sixteen units to obtain Iany selected amount of movement of said second bearing block in whole multiples of said unit.

References Cited by the Examiner UNITED STATES PATENTS 2,862,389 12/1958 Potter 74-1 2,931,237 4/1960 Backus 74-335 3,191,167 6/1965 McNaney 74-110 DAVID I. WILLIAMOWSKY, Primary Examiner.

H. S. LAYTON, Assistant Examiner. 

11. IN COMBINATION WITH A TRANSMISSION HAVING SHIFTABLE GEARS, HYDRAULIC MOTOR MEANS CONNECTED TO SAID GEARS TO EFFECT THE SHIFTING THEREOF, VALVE MEANS IN CIRCUIT WITH SAID HYDRAULIC MOTOR MEANS TO CONTROL THE MOVEMENT THEREOF, A SHAFT OPERATIVELY CONNECTED TO SAID VALVE MEMBER ROTATABLE FOR SHIFTING THE VALVE MEMBER, A ROTARY SERVO-MOTOR HAVING ITS OUTPUT SIDE CONNECTED TO SAID SHAFT, AND ACTUATOR MEANS FOR ADJUSTING THE INPUT SIDE OF SAID SERVO-MOTOR COMPRISING, A FRAME, SAID FRAME DEFINING A CHANNEL, A PLURALITY OF CAMS IN SERIAL RELATION IN THE CHANNEL HAVING FREEDOM TO ROTATE IN THE CHANNEL AN TO MOVE IN THE DIRECTION OF THE LENGTH OF THE CHANNEL, EACH CAM HAVING A LARGER DIAMETER AND A SMALLER DIAMETER, A STATIONARY FIRST BEARING BLOCK IN THE FRAME AT ONE END OF THE CHANNEL ON WHICH THE CAM AT ONE END OF THE SERIES OF CAMS RESTS, A MOVABLE SECOND BEARING BLOCK MOVABLY GUIDED IN THE FRAME SPACED ALONG THE CHANNEL FROM SAID FIRST BEARING BLOCK AND ENGAGED BY THE CAM AT THE OTHER END OF SAID SERIES OF CAMS, A ROTARY ACTUATOR FOR EACH CAM MOUNTED ON THE FRAME, A FLEXIBLE DRIVE CONNECTION FROM EACH ACTUATOR TO ITS RESPECTIVE CAM, EACH ACTUATOR BEING OPERABLE WHEN ENERGIZED TO ROTATE ITS RESPECTIVE CAM TO POSITION THE LARGER DIAMETER THEREOF IN THE DIRECTION OF THE LENGTH OF SAID CHANNEL AND WHEN DE-ENERGIZED TO ROTATE THE RESPECTIVE CAM TO POSITION THE SMALLER DIAMETER THEREOF IN THE DIRECTION OF THE LENGTH OF THE CHANNEL, AND MEANS FOR SELECTIVELY ENERGIZING SAID ACTUATORS, SAID SECOND BEARING BLOCK BEING OPERATIVELY CONNECTED WITH THE INPUT SIDE OF SAID SERVO-MOTOR. 